Combination use of immune complexes and a Ca2(+) channel blocker azelnidipine enhances interleukin-12 p40 secretion without T helper type 17 cytokine secretion in human monocyte-derived dendritic cells

Structure-activity relationship of dihydropyridines for rhabdomyosarcoma

Childhood muscle-related cancer rhabdomyosarcoma is a rare disease with a 50-year unmet clinical need for the patients presented with advanced disease. The rarity of ∼350 cases per year in North America generally diminishes the viability of large-scale, pharmaceutical industry driven drug development efforts for rhabdomyosarcoma. In this study, we performed a large-scale screen of 640,000 compounds to identify the dihydropyridine (DHP) class of anti-hypertensives as a priority compound hit. A structure-activity relationship was uncovered with increasing cell growth inhibition as side chain length increases at the ortho and para positions of the parent DHP molecule. Growth inhibition was consistent across n = 21 rhabdomyosarcoma cell line models. Anti-tumor activity in vitro was paralleled by studies in vivo. The unexpected finding was that the action of DHPs appears to be other than on the DHP receptor (i.e., L-type voltage-gated calcium channel). These findings provide the basis of a medicinal chemistry program to develop dihydropyridine derivatives that retain anti-rhabdomyosarcoma activity without anti-hypertensive effects.

Repositioning Azelnidipine as a Dual Inhibitor Targeting CD47/SIRPα and TIGIT/PVR Pathways for Cancer Immuno-Therapy

Strategies boosting both innate and adaptive immunity have great application prospects in cancer immunotherapy. Antibodies dual blocking the innate checkpoint CD47 and adaptive checkpoint PD-L1 or TIGIT could achieve durable anti-tumor effects. However, a small molecule dual blockade of CD47/SIRPα and TIGIT/PVR pathways has not been investigated. Here, an elevated expression of CD47 and PVR was observed in tumor tissues and cell lines analyzed with the GEO datasets and by flow cytometry, respectively. Compounds approved by the FDA were screened with the software MOE by docking to the potential binding pockets of SIRPα and PVR identified with the corresponding structural analysis. The candidate compounds were screened by blocking and MST binding assays. Azelnidipine was found to dual block CD47/SIRPα and TIGIT/PVR pathways by co-targeting SIRPα and PVR. In vitro, azelnidipine could enhance the macrophage phagocytosis when co-cultured with tumor cells. In vivo, azelnidipine alone or combined with irradiation could significantly inhibit the growth of MC38 tumors. Azelnidipine also significantly inhibits the growth of CT26 tumors, by enhancing the infiltration and function of CD8⁺ T cell in tumor and systematic immune response in the tumor-draining lymph node and spleen in a CD8⁺ T cell dependent manner. Our research suggests that the anti-hypertensive drug azelnidipine could be repositioned for cancer immunotherapy.

Verification of the effects of calcium channel blockers on the immune microenvironment of breast cancer

BACKGROUND

A higher density of tumor-infiltrating lymphocytes (TILs) can lead to greater therapeutic effects and improved prognoses in cancer treatment. Similar results have been observed in breast cancer, particularly in triple-negative breast cancer (TNBC) and human epidermal growth factor receptor 2-enriched breast cancer. Calcium channel blockers (CCBs) are antihypertensive drugs (AHTs) that have also been reported to suppress the functions of T cells and macrophages. In this study, we evaluated TILs before pre-operative chemotherapy (POC) in breast cancer and retrospectively analyzed the correlation between CCBs and TILs or prognosis.

METHODS

Of the patients treated with POC, 338 who had evaluable TILs were enrolled in this study. The correlations among TILs were evaluated according to standard methods, and CCB use and prognosis were investigated retrospectively.

RESULTS

Before POC, 65 patients (19.2%) took AHTs (CCBs: 41/338, 12.1%). The TIL density was significantly lower among patients administered CCBs for the group of all patients and for patients with TNBC (p = 0.040, p = 0.009, respectively). Additionally, patients with TNBC who were administered CCBs showed significantly lower response rates for POC (p = 0.040). In all patients receiving POC, no significant differences in disease-free survival (DFS) or overall survival (OS) were observed in patients administered CCBs (p = 0.712, p = 0.478, log-rank tests, respectively). Furthermore, no significant differences were found, even in patients with TNBC (DFS: p = 0.441, OS: p = 0.727, log-rank tests, respectively).

CONCLUSIONS

In patients with TNBC undergoing treatment for hypertension with CCBs, TILs in the needle biopsy specimens before treatment were significantly lower, and the response rate of POC was not sufficient. Thus, the immunosuppressive effects of CCBs may also affect the immune microenvironment.

Verapamil results in increased blood levels of oncolytic adenovirus in treatment of patients with advanced cancer

Calcium channel blockers including verapamil have been proposed to enhance release and antitumor efficacy of oncolytic adenoviruses in preclinical studies but this has not been studied in humans before. Here, we studied if verapamil leads to increased replication of oncolytic adenovirus in cancer patients, as measured by release of virions from tumor cells into the systemic circulation. The study was conducted as a matched case-control study of advanced cancer patients treated with oncolytic adenoviruses with or without verapamil. We observed that verapamil increased mean virus titers present in blood after treatment (P < 0.05). The frequency or severity of adverse events was not increased, nor were cytokine responses or neutralizing antibody levels different between groups. Signs of possible treatment-related clinical benefits were observed in both groups, but there was no significant difference in responses or survival. Thus, our data suggests that the combination of verapamil with oncolytic adenoviruses is safe and well tolerated. Moreover, verapamil treatment seems to result in higher virus titers in blood, indicating enhanced overall replication in tumors. A randomized trial is needed to confirm these findings and to study if enhanced replication results in benefits to patients.

Calcium channel blockers and modulation of innate immunity

PURPOSE OF REVIEW

Researchers and physicians are gaining more understanding of the utility of calcium channel blockers (CCBs) especially in modulation of innate immunity, and choose suitable ones in clinical practice. This review summarizes the recent related research findings.

RECENT FINDINGS

Sustained and/or dysregulated expression of pro-inflammatory cytokines is sufficient to produce tissue injury and provoke overt cardiac decompensation. The important question that remains to be addressed is whether or not it will be possible to modulate the inappropriate or maladaptive consequences of innate immune activation and pro-inflammatory cytokine expression in the mammalian heart. CCBs, such as nifedipine, amlodipine, diltiazem, and verapamil, promote the relaxation of cardiac and smooth muscle cells by inhibiting calcium influx through calcium channels and calcium release from intracellular stores, and are commonly used in the treatment of cardiovascular disorders. Recently, several in-vitro studies have shown that, besides the effects they exert on muscle cells, CCBs also suppress the activation of various participants in immune reactions, including T cells, mast cells and macrophages, suggesting that they can be immunosuppressant.

SUMMARY

CCBs maybe suppress the activation of various participants in immune reactions.